Abstract: The cooling channels of injection mould play a crucial
role in determining the productivity of moulding process and the
product quality. It’s not a simple task to design high quality cooling
channels. In this paper, an intelligent cooling channels design system
including automatic layout of cooling channels, interference checking
and assembly of accessories is studied. Automatic layout of cooling
channels using genetic algorithm is analyzed. Through integrating
experience criteria of designing cooling channels, considering the
factors such as the mould temperature and interference checking, the
automatic layout of cooling channels is implemented. The method of
checking interference based on distance constraint algorithm and the
function of automatic and continuous assembly of accessories are
developed and integrated into the system. Case studies demonstrate the
feasibility and practicality of the intelligent design system.
Abstract: The aim of this paper is to propose a novel technique
to guarantee Quality of Service (QoS) in a highly dynamic
environment. The MANET changes its topology dynamically as the
nodes are moved frequently. This will cause link failure between
mobile nodes. MANET cannot ensure reliability without delay. The
relay node is selected based on achieving QoS in previous
transmission. It considers one more factor Connection Existence
Period (CEP) to ensure reliability. CEP is to find out the period
during that connection exists between the nodes. The node with
highest CEP becomes a next relay node. The relay node is selected
dynamically to avoid frequent failure. The bandwidth of each link
changed dynamically based on service rate and request rate. This
paper proposes Active bandwidth setting up algorithm to guarantee
the QoS. The series of results obtained by using the Network
Simulator (NS-2) demonstrate the viability of our proposed
techniques.
Abstract: Stochastic User Equilibrium (SUE) model is a widely
used traffic assignment model in transportation planning, which is
regarded more advanced than Deterministic User Equilibrium (DUE)
model. However, a problem exists that the performance of the SUE
model depends on its error term parameter. The objective of this
paper is to propose a systematic method of determining the
appropriate error term parameter value for the SUE model. First, the
significance of the parameter is explored through a numerical
example. Second, the parameter calibration method is developed
based on the Logit-based route choice model. The calibration process
is realized through multiple nonlinear regression, using sequential
quadratic programming combined with least square method. Finally,
case analysis is conducted to demonstrate the application of the
calibration process and validate the better performance of the SUE
model calibrated by the proposed method compared to the SUE
models under other parameter values and the DUE model.
Abstract: Identification and selection of appropriate product and
manufacturing technologies are key factors for competitiveness and
market success of technology-based companies. Therefore, many
companies perform technology intelligence (TI) activities to ensure
the identification of evolving technologies at the right time.
Technology monitoring is one of the three base activities of TI,
besides scanning and scouting.
As the technological progress is accelerating, more and more
technologies are being developed. Against the background of limited
resources it is therefore necessary to focus TI activities. In this paper
we propose a concept for defining appropriate search fields for
technology monitoring. This limitation of search space leads to more
concentrated monitoring activities. The concept will be introduced
and demonstrated through an anonymized case study conducted
within an industry project at the Fraunhofer Institute for Production
Technology IPT.
The described concept provides a customized monitoring
approach, which is suitable for use in technology-oriented companies.
It is shown in this paper that the definition of search fields and search
tasks are suitable methods to define topics of interest and thus to
align monitoring activities. Current as well as planned product,
production and material technologies and existing skills, capabilities
and resources form the basis for derivation of relevant search areas.
To further improve the concept of technology monitoring the
proposed concept should be extended during future research e.g. by
the definition of relevant monitoring parameters.
Abstract: Hot aqueous and methanol extracts of the two selected
herbal medicines such are Vellarugu chooranam (V.C) and
Amukkirai Chooranam (A.C) were examined for total phenolic and
flavonoid contents and in vitro antioxidant activity using four
different methods. The total phenolic and flavonoid contents in
methanol extract of V.C were found to be higher (44.41±1.26mg
GAE/g; 174.44±9.32mg QE/g) than in the methanol extract of A.C
(20.56±0.67mg GAE/g; 7.21±0.85mg QE/g). Hot methanol and
aqueous extracts of both medicines showed low antioxidant activity
in DPPH, ABTS, and FRAP methods and Iron chelating activity not
found at highest possible concentration. V.C contains higher
concentrations of total phenolic and flavonoid contents than A.C and
can also exert greater antioxidant activity than A.C, although the
activities demonstrated were lower than the positive control Trolox.
The in vitro antioxidant activity was not related with the total
phenolic and flavonoid contents of the methanol and aqueous extracts
of both herbal medicines (A.C and V.C).
Abstract: Nonstandard tests are necessary for analyses and
verification of new developed structural and technological solutions
with application of composite materials. One of the most critical
primary structural parts of a typical aerospace structure is T-joint.
This structural element is loaded mainly in shear, bending, peel and
tension. The paper is focused on the shear loading simulations. The
aim of the work is to obtain a representative uniform distribution of
shear loads along T-joint during the mechanical testing. A new
design of T-joint test procedure, numerical simulation and
optimization of representative boundary conditions are presented.
The different conditions and inaccuracies both in simulations and
experiments are discussed. The influence of different parameters on
stress and strain distributions is demonstrated on T-joint made of
CFRP (carbon fibre reinforced plastic). A special test rig designed by
VZLU (Aerospace Research and Test Establishment) for T-shear test
procedure is presented.
Abstract: A relationship between face and signature biometrics
is established in this paper. A new approach is developed to predict
faces from signatures by using artificial intelligence. A multilayer
perceptron (MLP) neural network is used to generate face details
from features extracted from signatures, here face is the physical
biometric and signatures is the behavioural biometric. The new
method establishes a relationship between the two biometrics and
regenerates a visible face image from the signature features.
Furthermore, the performance efficiencies of our new technique are
demonstrated in terms of minimum error rates compared to published
work.
Abstract: Age ratings are very helpful in providing parents with
relevant information for the purchase and use of digital technologies
by the children; this is why the non-definition of age ratings for the
use of ICTs by children in schools is a major concern; and this
problem serves as a motivation for this study whose aim is to
examine the factors affecting the perceptions of educators on the
learners’ youngest age for the introduction of ICTs in schools. This
aim is achieved through two types of research objectives: the
identification and design of theories and models on age ratings, and
the empirical testing of such theories and models in a survey of
educators from the Camperdown district of the South African
KwaZulu-Natal province. A questionnaire is used for the collection
of the data of this survey whose validity and reliability is checked in
SPSS prior to its descriptive and correlative quantitative analysis. The
main hypothesis supporting this research is the association between
the demographics of educators, their personality, and their
perceptions on the learners’ youngest age for the introduction of ICTs
in schools; as claimed by existing research; except that the present
study looks at personality from three dimensions: self-actualized
personalities, fully functioning personalities, and healthy
personalities. This hypothesis was fully confirmed by the empirical
study conducted by this research except for the demographic factor
where only the educators’ grade or class was found to be associated
with the personality of educators.
Abstract: In this paper, design of solid-state battery/supercapacitor emulator based on dc-dc boost converter is described.
The emulator mimics charging behavior of any storage device based
on a predefined behavior set by the user. The device is operated by a
two-level control structure: high-level emulating controller and low-
level input voltage controller. Simulation and experimental results are
shown to demonstrate the emulator operation.
Abstract: In the culture of Thailand, the Yak serve as a mediated
icon representing strength, power, and mystical protection not only
for the Buddha, but for population of worshipers. Originating from
the forests of China, the Yak continues to stand guard at the gates of
Buddhist temples. The Yak represents Thai culture in the hearts of
Thai people. This paper presents a qualitative study regarding the
curious mix of media, culture, and religion that projects the Yak of
Thailand as a larger than life message throughout the political,
cultural, and religious spheres. The gate guardians, or gods as they
are sometimes called, appear throughout the religious temples of
Asian cultures. However, the Asian cultures demonstrate differences
in artistic renditions (or presentations) of such sentinels. Thailand
gate guards (the Yak) stand in front of many Buddhist temples, and
these iconic figures display unique features with varied symbolic
significance. The temple (or wat), plays a vital role in every
community; and, for many people, Thailand’s temples are the
country’s most endearing sights. The authors applied folknography as
a methodology to illustrate the importance of the Thai Yak in serving
as meaningful icons that transcend not only time, but the culture,
religion, and mass media. The Yak represents mythical, religious,
artistic, cultural, and militaristic significance for the Thai people.
Data collection included interviews, focus groups, and natural
observations. This paper summarizes the perceptions of the Thai
people concerning their gate sentries and the relationship,
communication, connection, and the enduring respect that Thai
people hold for their guardians of the gates.
Abstract: Theoretical optimization of a copper-water negative
inclination heat pipe with internal composite wick structure had been
performed, regarding a new introduced parameter: the ratio between
the coarse mesh wraps and the fine mesh wraps of the composite
wick. Since in many cases, the design of a heat pipe matches specific
thermal requirements and physical limitations, this work
demonstrates the optimization of a 1m length, 8mm internal diameter
heat pipe without an adiabatic section, at a negative inclination angle
of -10º. The optimization is based on a new introduced parameter, LR:
the ratio between the coarse mesh wraps and the fine mesh wraps.
Abstract: Different order modulations combined with different
coding schemes, allow sending more bits per symbol, thus achieving
higher throughputs and better spectral efficiencies. However, it must
also be noted that when using a modulation technique such as 64-
QAM with less overhead bits, better signal-to-noise ratios (SNRs) are
needed to overcome any Inter symbol Interference (ISI) and maintain
a certain bit error ratio (BER). The use of adaptive modulation allows
wireless technologies to yielding higher throughputs while also
covering long distances. The aim of this paper is to implement an
Adaptive Modulation and Coding (AMC) features of the WiMAX
PHY in MATLAB and to analyze the performance of the system in
different channel conditions (AWGN, Rayleigh and Rician fading
channel) with channel estimation and blind equalization. Simulation
results have demonstrated that the increment in modulation order
causes to increment in throughput and BER values. These results
derived a trade-off among modulation order, FFT length, throughput,
BER value and spectral efficiency. The BER changes gradually for
AWGN channel and arbitrarily for Rayleigh and Rician fade
channels.
Abstract: Information and Communication Technologies (ICTs)
are pervasive nowadays, including in education where they are
expected to improve the performance of learners. However, the hope
placed in ICTs to find viable solutions to the problem of poor
academic performance in schools in the developing world has not yet
yielded the expected benefits. This problem serves as a motivation to
this study whose aim is to examine the perceptions of educators on
the advantages and disadvantages of e-learning. This aim will be
subdivided into two types of research objectives. Objectives on the
identification and design of theories and models will be achieved
using content analysis and literature review. However, the objective
on the empirical testing of such theories and models will be achieved
through the survey of educators from different schools in the
Pinetown District of the South African Kwazulu-Natal province.
SPSS is used to quantitatively analyse the data collected by the
questionnaire of this survey using descriptive statistics and Pearson
correlations after assessing the validity and the reliability of the data.
The main hypothesis driving this study is that there is a relationship
between the demographics of educators’ and their adherence to
learning theories on one side, and their perceptions on the advantages
and disadvantages of e-learning on the other side, as argued by
existing research; but this research views these learning theories
under three perspectives: educators’ adherence to self-regulated
learning, to constructivism, and to progressivism. This hypothesis
was fully confirmed by the empirical study except for the
demographic factor where teachers’ level of education was found to
be the only demographic factor affecting the perceptions of educators
on the advantages and disadvantages of e-learning.
Abstract: This paper presents a model predictive control (MPC)
of a utility interactive (UI) single phase inverter (SPI) for a
photovoltaic (PV) system at residential/distribution level. The
proposed model uses single-phase phase locked loop (PLL) to
synchronize SPI with the grid and performs MPC control in a dq
reference frame. SPI model consists of boost converter (BC),
maximum power point tracking (MPPT) control, and a full bridge
(FB) voltage source inverter (VSI). No PI regulators to tune and
carrier and modulating waves are required to produce switching
sequence. Instead, the operational model of VSI is used to synthesize
sinusoidal current and track the reference. Model is validated using a
three kW PV system at the input of UI-SPI in Matlab/Simulink.
Implementation and results demonstrate simplicity and accuracy, as
well as reliability of the model.
Abstract: Copper being one of the major intrinsic residual
impurities in steel possesses the tendency to induce severe
microstructural distortions if not controlled within certain limits.
Hence, this paper investigates the effect of this element on the
mechanical properties of construction steel with a view to ascertain
its safe limits for effective control. The experiment entails collection
of statistically scheduled samples of hot rolled profiles with varied
copper concentrations in the range of 0.12-0.39 wt. %. From these
samples were prepared standard test specimens subjected to tensile,
impact, hardness and microstructural analyses. Results show a rather
huge compromise in mechanical properties as the specimens
demonstrated 54.3%, 74.2% and 64.9% reduction in tensile strength,
impact energy and hardness respectively as copper content increases
from 0.12 wt. % to 0.39 wt. %. The steel’s abysmal performance is
due to the severe distortion of the microstructure occasioned by the
development of incoherent complex compounds which weaken the
pearlite reinforcing phase. It is concluded that the presence of copper
above 0.22 wt. % is deleterious to construction steel performance.
Abstract: This paper presents an anthropometric study
conducted to 300 employees in a maquiladora industry that belongs
to the cluster of medical products as part of a research project to
pretend simulate workplace conditions under which operators
conduct their activities. This project is relevant because traditionally
performed a study to design ergonomic workspaces according to
anthropometric profile of users, however, this paper demonstrates the
importance of making decisions when the infrastructure cannot be
adapted for economic whichever put emphasis on user activity.
Abstract: A circularly polarized fractal boundary microstrip
antenna is presented. The sides of a square patch along x- axis, yaxis
are replaced with Minkowski and Koch curves correspondingly.
By using the fractal curves as edges, asymmetry in the structure is
created to excite two orthogonal modes for circular polarization (CP)
operation. The indentation factors of the fractal curves are optimized
for pure CP. The simulated results of the novel polyfractal antenna
are demonstrated.
Abstract: Cognitive Radio is a turning out technology that
empowers viable usage of the spectrum. Energy Detector-based
Sensing is the most broadly utilized spectrum sensing strategy.
Besides, it's a lot of generic as receivers doesn't would like any
information on the primary user's signals, channel data, of even the
sort of modulation. This paper puts forth the execution of energy
detection sensing for AM (Amplitude Modulated) signal at 710 KHz,
FM (Frequency Modulated) signal at 103.45 MHz (local station
frequency), Wi-Fi signal at 2.4 GHz and WiMAX signals at 6 GHz.
The OFDM/OFDMA based WiMAX physical layer with
convolutional channel coding is actualized utilizing USRP N210
(Universal Software Radio Peripheral) and GNU Radio based
Software Defined Radio (SDR). Test outcomes demonstrated the
BER (Bit Error Rate) augmentation with channel noise and BER
execution is dissected for different Eb/N0 (the energy per bit to noise
power spectral density ratio) values.
Abstract: The article demonstrates on a case study how it is
possible to identify MSD risk. It is based on a dissertation Risk
identification model of occupational diseases formation in relation to
the work activity that determines what risk can endanger workers who
are exposed to the specific risk factors. It is evaluated based on
statistical calculations. These risk factors are main cause of upperextremities
musculoskeletal disorders.
Abstract: The paper presents the results of clusterization by
Kohonen self-organizing maps (SOM) applied for analysis of array of
Raman spectra of multi-component solutions of inorganic salts, for
determination of types of salts present in the solution. It is
demonstrated that use of SOM is a promising method for solution of
clusterization and classification problems in spectroscopy of multicomponent
objects, as attributing a pattern to some cluster may be
used for recognition of component composition of the object.